the igneous rocks: they are generally volcanic type rocks.
Sedimentary rocks: rocks that are formed for the accumulation of sediments.
the metamorphic rocks: they are rocks characterized by the modification of others already existing in the interior of the earth by a process called metamorphism
The metamorphic rocks give a great clue to their formation and the group that belongs to us and that provides us with other rocks, as well as the rock that ignores its origin and constitution, part of the volcanoes.